DE 20 2012 003577 A1 describes a charging system such as described in the above Technical Field.
The traction battery of an electric vehicle can be recharged at a charging station via integrated contact assemblies which conduct charge current through electrical conductors and a connector assembly in the vehicle. The fraction battery can also be recharged at a charging station via contactless assemblies which inductively transmit charge current from a transformer coil at the charging station to a transformer coil of the vehicle.
Inductive charging devices enable convenient charging since no mutual physical connection of electrical contacts need to be made, and the transformer coils which are to be moved to approach one another can be positioned by automated mechanisms.
Directly connected charging devices are economical in their operation since they have higher efficiency and correspondingly smaller losses as compared to inductive charging devices. Directly connected charging devices have a simple design and are thus cost effective. A disadvantage is that electrical contact elements have to be physically joined to one another, which is generally carried out by manually connecting plug connector components.
DE 10 2009 010 120 A1 describes a charging system having an automated feed device for making the connection between electrical contact elements of the charge module at the charging station and electrical contact elements of the charge module at the electric vehicle. In this charging system, the vehicle has to be positioned precisely with respect to the charging station so that the contact elements of the charge modules can be brought together. DE 10 2009 010 120 A1 describes that the vehicle can be arranged on a conveyor belt to move longitudinally and transversely (similar to the situation in an automatic car wash) and be automatically brought into a position in which its contact elements lie opposite the mating contact elements of the charging station. Optical means may be used to aid in the positioning.
DE 10 2009 010 120 A1 describes end sections of bar-shaped contact elements of the charging station charge module being formed with a vaulted cross section allowing them to impinge upon slanted insertion surfaces of the contact elements of the vehicle charge module. The contact elements of the charging station charge module are not completely rigid, but instead are elastic enough so that they can also impinge on the mating contact elements of the vehicle charge module by undergoing small lateral deflections in the contacting direction.
In general, practical implementation of a charging system with motor driven electrical contact elements is not without problems. The connection of contact elements by machines requires precise knowledge of the positions of the contact elements to be connected, precise mechanical alignment of the contact elements with respect to one another, a “finely tuned” action during the connection and separation processes of the contact elements, and prevention of damage or wear to the contact elements. Care must be taken to assure that the contact elements are precisely aligned with one another during the connection process so that they do not jam. A charging system fulfilling these requirements is usually accompanied by significant technical effort and high cost.